Liaoceratops: a ‘missing link’ of the horned dinos?
28 March 2002
A team of American and Chinese paleontologists have discovered two small dinosaur skulls in China. This prompted headlines such as ‘Dino discovery fills in missing link’ because they were perceived as ‘Triceratops’ Tiny Ancestors’. The researchers published their findings in Nature 416(6878):314–317, 21 March 2002 (A ceratopsian dinosaur from China and the early evolution of Ceratopsia).
The researchers found two skulls which they named Liaoceratops yanzigouensis, after the Laioning province and Yanzigou village, while ‘–ceratops’ is the usual ending for horned dinosaur names, from Greek keras, kerat– horn and opsis face. They dated the finds at 128–139 Ma (millions of years) or possibly 145 Ma. The spokesman was Peter Makovicky, assistant curator of dinosaurs at Chicago’s Field Museum. Other team members include Mark Norell, an ardent advocate of the dino-to-bird theory who has discovered many alleged feathered dinosaurs such as Protarchaeopteryx and Caudipteryx and BPM 1 3-13; and Xu Xing, who helped expose the Archaeoraptor hoax.
The holotype, the single specimen selected by a discoverer to be the definitive example of a new species, was a skull 4.4 inches (11.1 centimetres) long. The animal was estimated to be about 3 feet (1 metre) long—about the size of a large hare. The other skull was only about half the size, and was considered a juvenile skull. The skull had a frill, which may have been for display but also functioned as an attachment for its powerful jaw muscles. Liaoceratops had a small horn facing sideways under each of its eyes, which the researchers claim wouldn’t have been much use in defence, so it supposedly had evolved for display.
Many evolutionists believe that the bipedal 2-metre-long Psittacosaurus (‘parrot lizard’, ‘dated’ 119–97.5 Ma) was an ancestor to the ceratopsians, or ‘horned dinosaurs’ (e.g. see psittacosaurids). But according to this paper, basal ceratopsians, of which Liaoceratops is claimed to be the most primitive, branched into the psittacosaurids and neoceratopsians, and much earlier than previously thought. The latter branch includes the elephant-sized Triceratops, the largest, commonest and most famous ceratopsian, and supposedly one of the last dinosaurs to become extinct.
Was it really a missing link?
As usual, although the mass media used such terms, the original paper, while pro-evolution, was not so forward. For example:
- Even the holotype skull was sub-adult, as shown by the incompletely closed sutures between skull pieces. One must wonder whether it’s really a young specimen of an already-known type of dinosaur. It wouldn’t be the first time this has happened. One creature was named Mussaurus (‘mouse lizard’) because it was only 9–16 inches long (18–37 cm) long. But the large eyes indicate that it was a baby, possibly of the 10 to 13 feet long (3–4 m) Coloradisaurus, a pro-sauropod like Plateosaurus (see Mussaurus).
- The horns may have just been underdeveloped because of the juvenile state of the specimen. For many vertebrates with horns, the horns only develop with sexual maturation. So these small horns may be more relevant to the study of dinosaur ontogeny (development) than phylogeny (evolution).
- Liaosaurus has features that spoil the idea of a smooth evolutionary progression. Rather, some structural similarities between different ceratopsians are now regarded as homoplasies, i.e. independently arisen and not the result of evolution from a common ancestor. This is consistent with separate creation. The homoplasies have also caused the researchers to reverse the previous order of evolution (phylogeny) in one case, showing how uncertain evolutionary theories are.
- Dinosaur taxonomy (classification) seems rife with ‘splitting’, i.e. different specimens of the same type of creature are given different names. E.g. with sauropods, the largest dinosaurs including Brachiosaurus, Diplodocus and Apatosaurus, 87 genera are commonly cited, but only 12 are ‘firmly established’ and another 12 are considered ‘fairly well established’ [McIntosh, J.S., Sauropoda; in Wieshampel, D.B. et al., The Dinosauria, University of California Press, Berkeley, p. 345, 1992]. In the theropods, the carnivorous dinosaurs including Allosaurus and T. rex, a genus Antrodemus was named, but this was based on a single damaged and incomplete vertebra, and was probably just an Allosaurus—see Antrodemus valens. So how many so-called ‘evolutionary progressions’ in the fossil record are really variations within a kind? Anyway, as shown in Dinosaurs: Phylogenetic Chart, gaps, not progressions, dominate.
(Article available in Spanish)